What two premium vehicles do you primarily use? Can you divulge your set up for those tanks? I'd like to replicate your success.
I didn't say two premium vehicles.
Mostly use fast moving/fast shooting low tier light tank: T-15, T-127, M3 Light, Tetrarach, LTP, Locust.. the more crew you have on the vehicle the faster the progress.
Fast moving light tank are expected to die in battle, most players do not consider you as a BOT when you rush out and die quickly.
Fast shooting to get more possible damage, you may not destroy enemy, but the more damage you cause, more EXP you will receive per battle.
I also use tier 5, Ram II and T-25 for better result in credit farming, but usually never longer than 6 hours in a day.
Avoid using heavy tanks with TL, most players look to heavy tanks for battle progression, very easily spotted as BOT if your heavy tank is driven by TL.